M38002M4 Datasheet, PDF (76/173 Pages) Mitsubishi Electric Semiconductor – 8-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATION
2.3 Serial I/O
2.3.3 Serial I/O connection examples
(1) Control of peripheral IC equipped with CS pin
There are connection examples using a clock synchronous serial I/O mode.
Figure 2.3.10 shows connection examples of a peripheral IC equipped with the CS pin.
(1) Only transmission
(using the RXD pin as an I/O port)
Port
SCLK
TXD
CS
CLK
DATA
3800 group Peripheral IC
(OSD controller etc.)
(2) Transmission and reception
Port
SCLK
TXD
RXD
3800 group
CS
CLK
IN
OUT
Peripheral IC
(E² PROM etc.)
(3) Transmission and reception
(Pins RXD and TXD are connected)
(Pins IN and OUT in peripheral IC
are connected)
Port
CS
SCLK
CLK
TXD
IN
RXD
OUT
3800 group ^T1 Peripheral IC^T2
(E² PROM etc.)
(4) Connecting ICs
Port
SCLK
TXD
RXD
Port
3800 group
CS
CLK
IN
OUT
Peripheral IC 1
T1: Select an N-channel open-drain output control of TXD pin.
2: Use such OUT pin of peripheral IC as an N-channel open-
drain output in high impedance during receiving data.
Note: “Port” is an output port controlled by software.
CS
CLK
IN
OUT
Peripheral IC 2
Fig. 2.3.10 Serial I/O connection examples (1)
2-28
3800 GROUP USER’S MANUAL